The invention relates to an automatable measuring, cleaning and calibration device for pH-electrodes or electrodes for measuring redox potentials, specifically in process engineering, having an electrode armature which maintains the measuring electrode in an operating position or in a position for maintenance, where the electrode is retained in the maintenance position in a rinsing chamber in which a cleaning and calibration procedure can be carried out, and having a pump device to supply cleaning fluid and calibration solutions to the rinsing chamber by way of a delivery line connecting the pump device and the rinsing chamber.
Electrochemical sensors and their electrodes are only conditionally consistent with respect to their measurement characteristics as a result of the effects of temperature, type and concentration of ions in the test medium, contamination and ageing, and for this reason they should be cleaned at appropriate intervals and checked through the use of standardized calibration solutions. In an inspection of this kind sensor, parameters such as zero point and steepness of the sensor curve are captured through measurements and saved in the appropriate measurement and evaluation device for consideration during sensor operation.
An electrode armature for a measuring, cleaning and calibration device is described, for example, in DE 39 27 282 A Using an electrode armature of this type, a pH-electrode, for example, can be moved from its operating position in a process container and brought into a position for maintenance in a rinsing chamber, where it is exposed to cleaning and calibration solutions.
Further efforts are being made to automate this cleaning and calibration process, which is hereafter described as maintenance. The known method is to supply cleaning fluids and calibration solutions through pump equipment to the rinsing chamber of the measuring, cleaning and calibrating device. A separate pump device is used for each medium to be supplied.
The object of the present invention is to design a more compact version of an automatable measuring, cleaning and calibration device of the type described above.